Immunotherapy For Treating Allergies
Immunotherapy, also called allergy shots, is a preventive treatment for allergies. It involves a series of injections designed to make your body less sensitive to the allergens that trouble you. While immunotherapy doesn't actually cure allergies, it can greatly reduce allergy symptoms. It can be successful in up to 90% of people with seasonal nasal allergies. For those with year-round nasal allergies, it works 70% to 80% of the time.
How to decide. Immunotherapy isn't for everyone. It's not commonly used, for instance, with very young children, and it may be inappropriate for children of preschool age or younger and senior citizens. Many people choose immunotherapy when they can't avoid their allergens or get satisfactory results from allergy medication alone.
What to consider. There are drawbacks to the process itself. For instance, it takes years of weekly visits to the doctor's office to achieve results. In addition, the tolerance you build to allergens may not last forever.
Immunotherapy also involves a health risk, since you're injected with something to which you're allergic. If you do receive immunotherapy, your doctor will closely watch how you react.
How Immunotherapy Works to Treat Allergies
- Immunotherapy makes you less sensitive to the substances that cause your allergy symptoms.
- It is a long-term allergy treatment that can go on for years.
- It works by changing the way your body's immune system responds to allergens.
Allergy shots work like other types of vaccinations. The injection of a small amount of allergen causes your body to produce a substance, or antibody, that neutralizes the allergen's effect. Experts believe the process also "confuses" your immune system, changing how your body responds to allergy triggers. Eventually, your body "turns off" the antibodies producing nasal allergy symptoms.
With treatment, your body actually builds up immunity to the allergens that produce allergy symptoms. This doesn't happen overnight, but many people begin to feel better within months.
In immunotherapy, the allergy specialist injects small doses of allergens into the subcutaneous tissue just beneath the skin. These extracts are typically made from allergens to which you react during an allergy skin test. They might include substances people are commonly allergic to, such as pollens, mold spores, animal dander, or dust mites.
Immunotherapy starts out with weekly injections for up to 12 months, after which time the injections can be spaced to every other week, and eventually, to once a month. Allergy shots are then continued once a month for approximately 3-5 years. Sometimes the allergy shots are continued for even longer than 5 years.
To get the best results from immunotherapy, follow these guidelines:
- Continue allergy shots on a regular basis until treatment is discontinued.
- Wait for 20 to 30 minutes at your allergy specialist's office after receiving allergy shots so the staff can watch for any adverse reaction, such as a severe allergic reaction, also called an anaphylactic reaction. For more information, see Anaphylaxis.
- If you develop swelling at the injection site or a local skin reaction, apply ice and ask your doctor about oral antihistamines and about adjusting the dose of vaccine.
- Even after you leave your allergy specialist's office, watch for signs of a severe allergic reaction, including sneezing, watery nasal discharge, nausea, chest tightness, and dizziness. If any of these symptoms of a severe allergic reaction occur, get medical help immediately.
ABOUT THE AUTHOR
Written by Karen Serrano, MD Emergency Medicine resident at the University of Wisconsin-Madison.
Reviewed by Lisa V. Suffian, MD
Instructor of Clinical Pediatrics in the Division of Allergy and Pulmonary Medicine at Saint Louis Children's Hospital, Washington University School of Medicine
Assistant Clinical Professor in the Department of Pediatrics at Cardinal Glennon Children's Hospital, Saint Louis University
Board certified in Allergy and Immunology
Last updated June 2008